Active efforts have been made for development of storage cells that contain a magnetoresistance element consisting mainly of a tunnel insulating layer interposed between a free magnetization layer and a fixed magnetization layer. The magnetization direction of the fixed magnetization layer is fixed while that of the free magnetization layer is variable. Accordingly, a low resistance state where the magnetization direction of the fixed magnetization layer and that of the free magnetization layer coincide with each other and a high resistance state where the magnetization direction of the fixed magnetization layer and that of the free magnetization layer are in opposite directions can be switched by changing the magnetization direction of the free magnetization layer.
The known methods for changing the magnetization direction of a free magnetization layer include the use of an external magnetic field (for instance, see Japanese Unexamined Patent Publication (Kokai) No. 2009-152594), and the use of the spin torque effect of an electric current flowing through a magnetoresistance element.